Packaging of products, such as products in a shingled arrangement, can involve arranging the products on a tray or bottom web of film and overlaying with a top web of film to seal or cover the products. To ensure a hermetic and tight seal, it is common to draw a vacuum inside the package to form a vacuum sealed package. One such method of vacuum sealing the package is to seal the package along three edges, or if one is a fold, along two edges, and insert a vacuum device into the package through the unsealed portion in order to withdraw the air from the interior of the package. The vacuum device is then removed, and the package is subsequently sealed at its unsealed portion. One drawback with this method is that during the time it takes to remove the vacuum device and to subsequently seal the package, the potential exists for air to reenter the package. Various solutions to prevent air from reentering have included clamping the package opening closed until the air is evacuated; however, upon removing the clamp for sealing, the air can reenter the package.
Another method is to use vacuum on a flow wrapper package to produce a tight film over the product. However, a true vacuum can be difficult to achieve because air can get into the package from the folding box location. The film is folded around the folding box to provide a fold in a web of film to create two opposing panels to form two sides. As air is evacuated downstream of the folding box, it still can reenter from the folding box location because it is not yet sealed at the side edges adjacent the folding box.
Current vacuum package technology can utilize a vacuum tube having only an opening at its end to draw the vacuum. This single opening can pull on the film making it tighter at one spot, i.e., the spot where the single hole is, and can cause the film to wrinkle or bulge and to not lay flat when being sealed around the product, as well as being pulled tighter in one spot versus another.
Another method of vacuum sealing comprises evacuating air from a package while in an air tight chamber. First, the package containing the product therein is placed within the air chamber. Then, the air within the chamber is first evacuated, which subsequently evacuates the air inside of the package. The package can be sealed at the opening from which the air has been evacuated while still in the chamber, thus ensuring that the package remains generally free of air. However, this proves to be a time consuming process, taking significant time to evacuate air from the package because both the chamber and package have to be evacuated and resulting in much more air that has to be removed.